Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint and non-destructive, and the description is consistent with them while adding real value: the id is stable across token refresh, reconnection, and metadata changes, is never reassigned, is scoped to this app, and no name/email or other PII is read or returned. The key-plan rate-limit note is also disclosed. This is well beyond what the annotations convey.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The first sentence is front-loaded with the core behavior and the null case; subsequent sentences cover durability, PII exclusion, and limits. Most content earns its place, though the trailing "Read-only." merely restates the readOnlyHint annotation and the earlier framing, so there is minor waste.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema and no parameters, the description carries the return-value burden and does so: an opaque id or nothing, unique to the app, stable over time. The only small gap is not stating the concrete return type (string vs null vs wrapped object), which an agent must still infer.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The tool takes no parameters, so the baseline is 4. The description reinforces this implicitly by framing the credential context as the only input ("behind this request's authenticated credentials"), and no parameter explanation is needed.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb (return) and resource (the opaque id of the profile behind the authenticated credentials), plus the null case. No sibling tool exposes a profile identifier, so the distinction is clear from the wording alone.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicitly says to use it "to decide whether a profile exists before scoring a contract," which anchors it to the score_contract workflow and gives an ordering constraint. It also notes rate limits match search_contracts. No explicit exclusions or alternatives are named, but none are plausible for a zero-argument context probe.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.